Exterior Paint vs. Interior Paint: What’s the Difference?

Painting can be a great way to freshen up and add new colors to your living space. With warmer weather around the corner, you can now make good on your plans to not only paint indoor spaces, but outdoor ones as well. A quick trip to the store might raise some questions, however. Which paint do you use? Does it make a difference if you use interior paint outside and exterior paint inside? As it turns out, all paint is not created equal and depending on the job, you might want to be careful when choosing the right paint for you.

Here are three important things to remember, no matter what type of paint you end up purchasing:

Cost can be an indicator of paint quality. It should be considered when looking at how long an area will be covered in paint.

Use of the best paint grades will pay off in durability, especially on exterior surfaces.

Paint gloss and color will fade over time, especially those surfaces exposed to sunlight.

Paint formulated for outdoor use contain additives that can give them longevity in the elements, including resistance to cracking, fade prevention, mildew and mold resistance, resistance to tannin staining, general dirt resistance, as well as protection from the sun’s ultraviolet rays. To compensate for the variable temperature conditions, exterior paint also contains flexible resins to keep paint looking good when the surface underneath expands and contracts.

Interior paint doesn’t get rained on and will likely never be subject to a big freeze, so it is made with more rigid resins. These resins make interior paint less prone to damage from scuffing and easier to clean, as well. Interior paints are designed to withstand abrasion and to be low or zero VOC (volatile organic compounds). They are designed this way because they occupy the same space as we do. Even though you might not give it much thought, VOCs can play a huge part in your overall health.

The EPA states, “Understanding and controlling common pollutants indoors can help reduce your risk of indoor health concerns.” With that said, by today’s standards a low VOC paint has the same VOC levels as zero VOC paint from just 10 years ago. The zero VOC paints of today, which still have minute levels of VOCs, are the most gentle to date. Zero VOC paint does have a trade off, however, when it comes to scuff resistance. Low VOC paints have far superior abrasion resistance than zero VOC paints. Interior paints are generally gentler, so you have to be easier on them.

One might assume that because exterior paint has to stand up to more abuse, it will perform better indoors, but that’s not the case. Exterior paint is more prone to scuffing and scratches. It’s also typically going to release more VOCs as it cures, making it less healthy for indoor use.

The chemistry behind modern paints fine-tunes them for a specific use; interior paints inside and exterior paints outside. The number one thing to remember is to use the right paint for the project. Different paints are recommended for different applications for a simple reason – it’s what will give you the best results!

Need some more expert advice for your painting project? Give us a call and we’ll help you from start to finish.